The Primate Research Institute (PRI) of New Mexico State University proposes to establish a self-sustaining chimpanzee breeding colony of 76 animals which will produce 18 to 25 one-year old offspring per year. Approximately 12 infants will be retained each year to serve as eventual breeders. A growth rate of four adult breeders per year is anticipated after 10 years. The remaining infants will be provided to research programs of national importance. Two programs, now supported by PRI, which may use these animals are the government's hepatitis research effort by CDC, FDA and NIAID, and the AIDS vaccine-development program of NCI. The 90 animals proposed as candidates by PRI (29 males, 61 females) are all older than nine years and all but 12 are proven breeders. When screening for presence of Non A, Non B hepatitis is concluded, this list will be narrowed to 76 animals (19 males, 57 females). Twenty-four of these animals are available immediately. The remainder will become available 1 March 1987. A harem system (1 male, 3 females/harem) of breeding is proposed. This provides maximum genetic diversity, protection against disease transmission and excellent production. Each harem will be housed in a pair of large indoor-outdoor cages (2 animals per cage). Infants designated as breeding replacements will be left with their mothers for one year. After weaning, they will be housed in peer groups in large indoor-outdoor enclosures.